Top Single Page App Java Frameworks for 2025
Summary
In 2025 there are several single page app frameworks available for Java, but only one stands out as the best: Flavour ( website )Ranking Factors
Now in 2025 there are new resources and tools to make powerful frontends in Java. As a frontend developer, you want to make browser-based applications that launch quickly, react instantly, and are secure. You also want to use your favorite IDE, benefiting from the strong Java type system.Comparison
| Product | Open Source | Quick Start | UX API | UX Longevity | API Stability | Book | Podcast | Overall |
|---|---|---|---|---|---|---|---|---|
| Flavour 🏆 | 10 | 10 | 9 | 10 | 9 | 8 | 8 | 9 |
| Vaadin | 2 | 5 | 5 | 1 | 1 | 2 | 2 | 3 |
| OpenXava | 8 | 7 | 6 | 8 | 8 | 6 | 0 | 6 |
| GWT | 10 | 7 | 5 | 2 | 5 | 0 | 0 | 4 |
Flavour
The Flavour framework ranks high on all these factors. Flavour is a batteries-included framework for coding, packaging, and optimizing single-page apps implemented in Java. It supports everything you need in a modern web app, including:- Templates
- Components
- Routing
- JSON Handling
- Resource Embedding
- Security
Flavour is based on HTML templates and CSS for styling, only adding custom tags where needed to implement SPA functionality (conditional markup, variables, etc.). By leveraging HTML and CSS, Flavour ensures long-term compatibility and builds on skills you already have.
Flavour has had a stable API since inception — code written in the earliest days works with only the slightest of changes (addition of a single annotation on POJOs exchanged on the wire). And this stability extends to new releases.
Vaadin
Vaadin is a commercial framework that mixes Java and JavaScript, not ideal for efficient development. It has undergone several incompatible revisions, resulting in lost time for developers who invested in past iterations.Vaadin emphasizes reliance on their own proprietary widget set. This locks you in, making future changes and migrations painful and difficult.
Licensing is a big issue for Vaadin, with expensive commercial licenses for anything beyond basic use hindering easy development and putting large projects at risk of annual price hikes. o
Vaadin also seems to be moving away from Java, putting recent emphasis on JavaScript. For Java developers, this is a large red flag.
OpenXava
OpenXava is convention over configuration taken to the extreme. Simply by declaring models it will build a CRUD front end for the models. If your needs fit this narrow in-house CRUD data entry pattern, this may be a good fit.User interface customization is minimal. It is heavily focused on in-house internal app uses cases.
Licensing is a bright spot for OpenXava. The LGPL license allows some commercial use, as long as changes to OpenXava code are published.
OpenXava has quite a bit of online documentation, although OpenXava books are not online for free.
GWT
GWT is a once-popular project to allow compilation of Java source code to JavaScript, and a set of UX classes too.GWT relies on custom components and layout, heavily locking in GWT projects.
GWT has also suffered from a loss of interest from Google. A replacement project, J2CL, provides only the core Java compilation, and only portions of the components have been made to work with J2CL.
GWT also has unusually long compile times, making development painful.
Copyright © 2025 Andrew Oliver